Re: Refactoring postmaster's code to cleanup after child exit

Alexander Lakhin <exclusion@gmail.com>

From: Alexander Lakhin <exclusion@gmail.com>
To: Heikki Linnakangas <hlinnaka@iki.fi>, Thomas Munro <thomas.munro@gmail.com>
Cc: "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2024-08-18T08:00:00Z
Lists: pgsql-hackers
Hello Heikki,

10.08.2024 00:13, Heikki Linnakangas wrote:
>
> Committed the patches up to and including this one, with tiny comment changes.

I've noticed that on the current HEAD server.log contains binary data
(an invalid process name) after a child crash. For example, while playing
with -ftapv, I've got:
SELECT to_date('2024 613566758 1', 'IYYY IW ID');
server closed the connection unexpectedly

grep -a 'was terminated' server.log
2024-08-18 07:07:06.482 UTC|||66c19d96.3482f6|LOG:  `�!x� (PID 3441407) was terminated by signal 6: Aborted

It looks like this was introduced by commit 28a520c0b (IIUC, namebuf in
CleanupBackend() may stay uninitialized in some code paths).

Best regards,
Alexander



Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Fix test name and username used in failed connection attempts

  2. tests: Don't fail due to high default timeout in postmaster/003_start_stop

  3. tests: Fix race condition in postmaster/002_connection_limits

  4. Pass MyPMChildSlot as an explicit argument to child process

  5. Assign a child slot to every postmaster child process

  6. Kill dead-end children when there's nothing else left

  7. Replace postmaster.c's own backend type codes with BackendType

  8. Use an shmem_exit callback to remove backend from PMChildFlags on exit

  9. Add test for dead-end backends

  10. Add test for connection limits

  11. Fix garbled process name on backend crash

  12. Consolidate postmaster code to launch background processes

  13. Fix comment on processes being kept over a restart

  14. Refactor code to handle death of a backend or bgworker in postmaster

  15. Make BackgroundWorkerList doubly-linked

  16. Minor refactoring of assign_backendlist_entry()

  17. Fix outdated comment; all running bgworkers are in BackendList

  18. Allow building with MSVC and Strawberry perl

  19. Fix rare failure in LDAP tests.

  20. Allow notifications to bgworkers without database connections.